The lectures presented in this text deal to a large extent with algorithmic, programming and implementation issues, as well as experiences gained so far on parallel platforms. Attention is also given to mathematics aspects, notably: domain decomposition and scalable algorithms; parallelization strategies; programming aspects; parallel algorithms; applications in computational fluid dynamics; and the present hardware situation and developments to be expected. The book is addressed to students on a graduate level and researchers in industry engaged in scientific computing, who have little or no experience with high performance computing, but who want to learn more, and/or want to port their code to parallel platforms. It should be a good starting point for those who want to enter the field of high performance computing, especially if applications in fluid dynamics are envisaged.